Imaging studies after a first febrile urinary tract infection in young children

The most-cited articles in pediatric imaging: a bibliometric analysis

INTRODUCTION

The number of citations that an article has received reflects its impact on the scientific community. The purpose of our study was to identify and characterize the 51 most-cited articles in pediatric imaging.

EVIDENCE ACQUISITION

Based on the database of Journal Citation Reports, we selected 350 journals that were considered as potential outlets for pediatric imaging articles. The Web of Science search tools were used to identify the most-cited articles relevant to pediatric imaging within the selected journals.

EVIDENCE SYNTHESIS

The 51 most-cited articles in pediatric imaging were published between 1952 and 2011, with 1980-1989 and 2000-2009 producing 15 articles, each. The number of citations ranged from 576-124 and the number of annual citations ranged from 49.05-2.56. The majority of articles were published in pediatric and related journals (N.=26), originated in the USA (N.=23), were original articles (N.=45), used MRI as imaging modality (N.=27), and were concerned with the subspecialty of brain (N.=34). University College London School of Medicine (N.=6) and School of Medicine University of California (N.=4) were the leading institutions and Reynolds EO (N.=7) was the most voluminous author.

CONCLUSIONS

Our study presents a detailed list and an analysis of the most-cited articles in the field of pediatric imaging, which provides an insight into historical developments and allows for recognition of the important advances in this field.

Controversies Regarding Management of Vesico-ureteric Reflux

The primary goal in the management of a child with urinary tract infection (UTI) is to prevent recurrence of UTI and acquired renal damage. Approximately 15% of children develop renal scarring after a first episode of febrile UTI. Vesico-ureteric reflux (VUR) is diagnosed in 30-40% of children imaged after first febrile UTI. The 'top-down' approach involving ultrasound and dimercaptosuccinic acid scan (DMSA) first after an appropriate interval following UTI, can help in avoiding voiding cystourethrogram (VCUG), an invasive test with higher radiation exposure. The majority view remains that VCUG should be done after the second attack of UTI in girls and first attack of UTI in boys. Although the evidence in favour of antibiotic prophylaxis remains doubtful in preventing renal scars associated with VUR, it remains the first line treatment for high-grade reflux (grade 3-5) with an aim to prevent UTI and allow spontaneous resolution of VUR. Early identification and appropriate treatment of associated bowel bladder dysfunction is an essential part of successful medical management of VUR. Endoscopic treatment of VUR, using a bulking agent, is useful in grade 3 VUR. The main controversy regarding intervention (endoscopic/open surgical intervention) involves absence of strong evidence for these interventions in reducing renal scarring on randomized controlled trials. However, several recent trials have found the surgical interventions to be effective in reducing recurrent pyelonephritis and repeated hospital admissions.

Critical appraisal of the top-down approach for vesicoureteral reflux

Vesicoureteral reflux (VUR) has been linked to recurrent urinary tract infections (UTIs), renal scarring, hypertension, renal insufficiency and end-stage kidney disease. Different imaging strategies have been proposed to approach children presenting with UTI to sort out patients with significant VUR while minimizing patient morbidity, radiation exposure and financial burden. None of these imaging strategies is universally accepted. The“top-down approach” (TDA) aims at restricting the number of voiding cystourethrograms (VCUGs) and its associated morbidity while identifying patients with clinically-significant reflux. In this approach, children presenting with febrile UTIs are acutely investigated with dimercapto-succinic acid (DMSA) renal scans to identify patients with renal parenchymal inflammation. Those with evidence of renal affection are offered VCUG and late DMSA scan to identify VUR and permanent renal scarring, respectively. Although TDA could identify clinically-significant VUR with high sensitivity, it is not without limitations. The approach segregates patients based on the presence of DMSA cortical lesions omitting the morbidity and the economic burden of UTI. Additionally, some of DMSA lesions are attributed to congenital dysplasia and unrelated to UTI. Ionizing radiation exposure, financial costs, limited availability of DMSA scans in the acute setting, variability in interpreting the results and low yield of actionable findings on DMSA scans are some other limitations. In this review, we tried to address the drawbacks of the TDA and reinforce the value of patient-centered approach for VUR.

Imaging studies and biomarkers to detect clinically meaningful vesicoureteral reflux

The work-up of a febrile urinary tract infection is generally performed to detect vesicoureteral reflux (VUR) and its possible complications. The imaging modalities most commonly used for this purpose are renal-bladder ultrasound, voiding cystourethrogram and dimercapto-succinic acid scan. These studies each contribute valuable information, but carry individual benefits and limitations that may impact their efficacy. Biochemical markers are not commonly used in pediatric urology to diagnose or differentiate high-risk disease, but this is the emerging frontier, which will hopefully change our approach to VUR in the future. As it becomes more apparent that there is tremendous clinical variation within grades of VUR, the need to distinguish clinically significant from insignificant disease grows. The unfortunate truth about VUR is that recommendations for treatment may be inconsistent. Nuances in clinical decision-making will always exist, but opinions for medical versus surgical intervention should be more standardized, based on risk of injury to the kidney.

Incidence and risk factors of urinary tract infection in very low birth weight infants

OBJECTIVES

To describe the incidence and associated risk factors of urinary tract infection (UTI) in very low birth weight (VLBW) infants and to determine the value of diagnostic imaging studies after the first UTI episode before discharge from the neonatal intensive care unit (NICU).

METHODS

VLBW infants born during 2003-2012 were reviewed for UTI. In a nested case-control study, potential risk factors of UTI were compared between infants with UTI (cases) versus birth weight and gestational age matched controls. Renal ultrasonography (USG) and voiding cystourethrography (VCUG) results were reviewed in cases.

RESULTS

During the study period, 54.7% of urine culture specimens were collected by sterile methods. 3% (45/1,495) of VLBW infants met the study definition for UTI. UTI was diagnosed at mean postnatal age of 33.1±22.9 days. There was no significant difference in gender, ethnicity, antenatal steroid exposure, blood culture positive sepsis, ionotropic support, respiratory support and enteral feeding practices between cases and controls. Cases had a significantly higher cholestasis compared to controls (22% vs. 9% ; p = 0.03). However, cholestasis was not a significant predictor of UTI in the adjusted analysis [adjusted OR 2.38 (95% CI 0.84 to 6.80), p = 0.11]. Cases had higher central line days, parenteral nutrition days, total mechanical ventilation days, chronic lung disease, and length of stay compared to controls. Renal USG was abnormal in 37% and VCUG was abnormal in 17% of cases.

CONCLUSIONS

The incidence of UTI in contemporary VLBW infants is relatively low compared to previous decades. Since no significant UTI predictors could be identified, urine culture by sterile methods is the only reliable way to exclude UTI. The majority of infants with UTI have normal renal anatomy. UTI in VLBW infants is associated with increased morbidity and length of stay.

Nuclear Medicine in Pediatric Nephro-Urology: An Overview

In the context of ante-natally diagnosed hydronephrosis, the vast majority of children with a dilated renal pelvis do not need any surgical treatment, as the dilatation resolves spontaneously with time. Slow drainage demonstrated at Tc-99m-mercaptoacetyltriglycine (MAG3) renography does not necessarily mean obstruction. Obstruction is defined as resistance to urinary outflow with urinary stasis at the level of the pelvic-ureteric junction (PUJ) which, if left untreated, will damage the kidney. Unfortunately this definition is retrospective and not clinically helpful. Therefore, the identification of the kidney at risk of losing function in an asymptomatic patient is a major research goal. In the context of renovascular hypertension a DMSA scan can be useful before and after revascularisation procedures (angioplasty or surgery) to assess for gain in kidney function. Renal calculi are increasingly frequent in children. Whilst the vast majority of patients with renal stones do not need functional imaging, DMSA scans with SPECT and a low dose limited CT can be very helpful in the case of complex renal calculi. Congenital renal anomalies such as duplex kidneys, horseshoe kidneys, crossed-fused kidneys and multi-cystic dysplastic kidneys greatly benefit from functional imaging to identify regional parenchymal function, thus directing further management. Positron emission tomography (PET) is being actively tested in genito-urinary malignancies. Encouraging initial reports suggest that F-18-fluorodeoxyglucose (FDG) PET is more sensitive than CT in the assessment of lymph nodal metastases in patients with genito-urinary sarcomas; an increased sensitivity in comparison to isotope bone scans for skeletal metastatic disease has also been reported. Further evaluation is necessary, especially with the promising advent of PET/MRI scanners. Nuclear Medicine in paediatric nephro-urology has stood the test of time and is opening up to new exciting developments.

Neutrophil gelatinase-associated lipocalin: utility in urologic conditions

Neutrophil gelatinase-associated lipocalin (NGAL) is best known as a non-invasive early marker of acute kidney injury (AKI). However, recent published reports have described additional utility of both plasma NGAL (pNGAL) and urine NGAL (uNGAL) in various pathologic conditions within the pediatric urinary tract, including urinary tract infection, vesicoureteral reflux (VUR), renal scarring, and obstructive uropathy. These two forms of NGAL have different applications related to their mechanisms of upregulation: pNGAL can serve as a marker of systemic inflammatory conditions, whereas uNGAL is specific for insults to the renal epithelium. Therefore, pNGAL has good predictive accuracy in systemic inflammation associated with pyelonephritis and renal damage, while uNGAL is an effective marker for identifying infection within the genitourinary environment as well as subclinical renal damage as a result of scarring or obstruction. Continued work should focus on the effect of trending NGAL values in patients with pyelonephritis, VUR, and hydronephrosis, to determine if longitudinal NGAL patterns have value in predicting adverse outcomes.

[Urinary tract infections in children]

Urinary tract infections (UTI) are the most common bacterial infections in children. The symptoms are not very specific and range from abdominal pain, poor feeding to nocturnal urinary incontinence. The technique of collecting urine plays an important role for securing the diagnosis. The best way to obtain urine in non-toilet-trained children is catheterization or suprapubic bladder aspiration. In toilet-trained children midstream urine is an acceptable alternative after cleaning the foreskin or labia. In the case of an infection a prompt empirical antibiotic therapy is necessary to reduce the risk of parenchymal scarring of the kidneys. There are different approaches to diagnose vesicoureteral reflux in different countries. The commonly used standard approach in Germany is voiding cystourethrography. In the case of reflux dimercaptosuccinic acid (DMSA) scintigraphy should be performed additionally to exclude renal scarring (bottom-up approach).

Decreased Identification of Vesicoureteral Reflux: A Cautionary Tale

AIM

To find the trend in patient's visits to our centers for vesicoureteral reflux (VUR). We hypothesize that VUR diagnosis and hence possible nephropathy recognition may be diminishing because of changing practice patterns.

METHODS

Data were extracted from electronic medical records for new and follow-up patients aged 0-18 years with ICD-9/10 codes to correspond with VUR, VUR unilateral, VUR bilateral, and VUR with reflux nephropathy, as well as new patients with diagnoses of urinary tract infections (UTI) and pyelonephritis at two major pediatric centers from 2012 to 2015. Figures and statistics to reflect absolute clinic visits and annual trends were created with SPSS 2010. Linear regression was applied.

RESULTS

Annually, Le Bonheur Children's Hospital and Nationwide Children's Hospital experienced an average decrease of 13 and 17% in total VUR visits, and an average decrease of 22 and 27% in VUR nephropathy visits, respectively, for each institution. Patient visits for UTIs were reduced an average of 16% annually in both centers. Linear regression demonstrated that number of patients (patients/year ± SE) decreased annually 69 ± 19 (P = 0.02), 7 ± 2 (P = 0.02), and 67 ± 25 (P = 0.04) for VUR, VUR nephropathy, and UTI, respectively.

CONCLUSION

We conclude that the decreased number of VUR and VUR nephropathy cases identified in subspecialty clinics (Nephrology/Urology) at two major children's hospitals reflect a possible decreased identification of VUR. This trend may also be due to decreased referral of low grade cases of VUR. We cannot conclude that "undifferentiated UTI" referrals increased concomitantly to account for the decreased VUR as our data reflects a decreased trend in those visits as well. We suggest that clinicians following the American Academy of Pediatrics guidelines ensure that all UTI are accounted for and surveillance is appropriately escalated for recurrent UTI or abnormal imaging results.

To screen or not to screen for vesicoureteral reflux in children with ureteropelvic junction obstruction: a systematic review

Ureteropelvic junction obstruction (UPJO) and vesicoureteral reflux (VUR) are the most common uropathies. The co-occurrence of both anomalies has led to the practice of screening for VUR in children with UPJO to prevent deterioration of kidney function due to renal scarring following urinary tract infections (UTIs). We determined the prevalence of VUR in children with UPJO for a critical assessment of VUR screening by voiding cystourethrography (VCUG). A systematic search strategy in MEDLINE, EMBASE, and CENTRAL was carried out for all articles that included VCUG, and renal scintigraphy or any other appropriate imaging technique for the diagnosis of UPJO. Twenty studies were eligible for inclusion. We found a pooled prevalence for VUR of 8.2 % (95 % CI = 3.6-12.7), about a threefold increase compared to the general pediatric population. VUR occurred bilateral or contralateral to the kidney with UPJO in 5.7 % (95 % CI = 3.0-8.5), equivalent to 75 % of all children with VUR. Considering the effect size of VUR treatment with antibiotics, about 207 and 278 children would need to undergo VCUG to prevent one febrile UTI and one case of renal scarring by 1-2 years, respectively.

CONCLUSION

Against this background, screening for VUR needs to be scrutinized and restricted to selected risk groups. What is known: • Screening of patients with ureteropelvic junction obstruction (UPJO) for vesicoureteral reflux (VUR) is recommended based on a small number of repeatedly cited studies. • The lack of conclusive evidence results in different treatment strategies and leads to difficulties when communicating diagnoses and treatment options to parents. What is new: • A robust prevalence for VUR in children with UPJO based on all published evidence and the resulting number needed to screen are given for decision-making in daily clinical practice. • The results may be a precursor for implementation into guidelines.

Delayed treatment of the first febrile urinary tract infection in early childhood increased the risk of renal scarring

AIM

This study evaluated the controversial relationship between the duration of fever before treatment initiation (FBT) for a febrile urinary tract infection (UTI), with renal scarring based on dimercaptosuccinic acid scintigraphy (DMSA) findings.

METHODS

The inpatient records of 148 children under two years of age with a first episode of febrile UTI were analysed. Acute and repeat DMSA findings, and clinical and laboratory parameters were evaluated.

RESULTS

Acute DMSA showed that 76 of the 148 children with a febrile UTI had renal lesions: 20 were mild, and 56 were moderate or severe. Repeat DMSA showed renal scarring in 34 patients. The only factors associated with the development of renal scars in the repeat DMSA were FBT of more than 72 hours, the presence and severity of vesicoureteral reflux and increased procalcitonin levels and absolute neutrophil counts. Multiple regression analysis showed that an FBT above 72 hours was the only significant factor that predicted renal scars.

CONCLUSION

Delay in treatment initiation of 72 hours or more was a risk factor for permanent renal scars after the first episode of febrile UTI. Other associated factors were increased procalcitonin and absolute neutrophil count on admission and the presence and severity of vesicouretal reflux.

Improving clean-catch contamination rates: A prospective interventional cohort study

OBJECTIVES

The clean-catch method of urine collection carries a high contamination rate. This study aims to evaluate the effects on contamination rate of providing a parent handout and pre-made urine collection pack for clean-catch urine collection.

METHODS

We conducted a single-centre prospective cohort interventional study in a tertiary paediatric ED. All children younger than 24 months who presented from April 2013 to June 2014 requiring a urine sample to be obtained were included. The intervention was provision of a pre-made urine collection pack including a standardised information handout. The primary outcome measure was the difference in proportion of urine contamination in samples obtained via a clean-catch pre- and post-intervention.

RESULTS

The total number of urine specimens included was 288 in the pre-intervention group and 333 in the post-intervention group. Contamination rates were 14.9% in the pre-intervention group and 11.4% in the post-intervention group. There was no statistically significant reduction in contamination (P = 0.19). The contamination rates appeared to be associated with gender, with (pooled) female contamination rates being 16.4% (44/269) and male contamination rates being 10.5% (37/352). Most specimens of urine were collected via the clean-catch method (81.2%), followed by catheter urine specimen (13.7%) and suprapubic aspirate (5.1%). The contamination rate in our study for clean-catch urine collectively was 13%, catheter urine specimen 3.8% and suprapubic aspirate 0%.

CONCLUSION

The contamination rate of clean-catch urine did not improve with the implementation of a pre-made urine collection pack including standardised written instructions.

Long-term impact of unilateral hypo/dysplastic kidney in infants with primary vesicoureteral reflux

INTRODUCTION

Renal abnormality is not a rare finding in infants with primary VUR. The pathophysiology of the renal abnormality is considered to be congenital or acquired. Congenital hypo/dysplastic kidney is a common finding in infants with primary VUR, especially in boys. However, the long-term impact of unilateral hypo/dysplastic kidney has not been elucidated. The aim of the current study is to clarify the long-term impact of unilateral hypo/dysplastic kidney with primary vesicoureteral reflux diagnosed in infancy.

MATERIAL AND METHODS

The medical records of patients with primary VUR detected in infancy with unilateral hypo/dysplastic kidney on initial nuclear renal scan (<40% relative renal function) and no scar on the contralateral kidney were reviewed retrospectively. Among them, 29 patients who were followed for more than 5 years were included in this study. Their clinical outcomes including chronic kidney disease (CKD) stage using estimated glomerular filtration rate (GFR) and the incidences of hypertension and proteinuria were analyzed.

RESULTS

Mean age at final visit was 12.4 years (range 5.9-22.2). Estimated GFR was evaluated in 26 patients at a mean age of 12.0 years (5.9-22.2). CKD stage was 1 in all. According to the guidelines of the Japanese Society of Hypertension, while none exceeded the standard level of systolic blood pressure (BP), two patients slightly exceeded the standard level of diastolic BP. In addition, no significant proteinuria was detected in all patients, although microalbuminemia was detected in 7.7% of patients.

DISCUSSION

The prognosis of reflux nephropathy depends on the remnant renal tissue mass, that is, the number of normal nephrons. The normal congenital solitary kidney is reported to be hyperplastic with normal-sized glomeruli rather than hypertrophic ones with larger nephrons, and to have better long-term outcome regarding renal function. Accordingly, we speculated that patients with unilateral hypo/dysplastic kidney would have a similar number of nephrons to those without hypo/dysplastic kidney who have no or minimal scar as far as the contralateral kidney is well preserved. Long-term outcome of the current retrospective study was consistent with our speculation in terms of estimated GFR, proteinuria, or hypertension.

CONCLUSIONS

The present study demonstrated that significant clinical findings related to unilateral hypo/dysplastic kidney detected in infancy were rarely observed in the long term. Accordingly, unilateral hypo/dysplastic kidney seems to be a benign condition. To confirm this finding, further follow-up of these patients is necessary.

A novel approach to evaluating the benefit of post-urinary tract infection renal ultrasonography, using decision curve analysis

BACKGROUND

The benefit of post-urinary tract infection (UTI) sonography to detect clinically significant renal abnormalities remains a subject open to debate. Decision curve analysis (DCA) is a novel method for evaluating the clinical usefulness of diagnostic tests. Our objective was to determine, using DCA, the benefit of post-UTI sonography and of post-UTI sonography with biological markers of inflammation to predict the risk of recurrence of febrile UTI in children aged 2 to 24 months without known uropathy.

METHODS

We retrospectively analyzed all children aged 2 to 24 months, without known uropathy, who presented with a first episode of febrile UTI between 2009 and 2012 and followed them for 30 months. We then used DCA to estimate the benefit of post-UTI sonography or post-UTI sonography + biological markers of inflammation for detecting the risk of recurrence.

RESULTS

A total of 318 children [144 boys (45.3 %) and 174 girls (54.7 %)], with a mean age of 6.9 ± 5.6 months, were identified. Of these, 210 children presented with a significant inflammation [66.2 %; 95 % confidence interval (CI) 61.0-71.4], and 30 (9.4 %; 95 % CI 6.2-12.6) presented with abnormal post-UTI sonographic findings. Eighteen (5.7 %; 95 % CI 3.1-8.2) children presented with recurrent UTI at 30 months.

CONCLUSIONS

There were significantly more recurrences in those children who presented with abnormal sonographic findings than in those who did not (relative risk 7.68; 95 % CI 3.03-19.46). However, taking into account the effect of false-positives and false negatives, the DCA revealed that for threshold probabilities of >30 %, at which patients/doctors are concerned about unnecessary interventions (whether tests or treatments), neither post-UTI sonography nor post-UTI sonography + biological markers of inflammation have sufficient value to improve care.

Evaluation of a New Strategy for Clean-Catch Urine in Infants

BACKGROUND AND OBJECTIVES

A new noninvasive bladder stimulation technique has been described to obtain clean-catch urine (CCU) in infants aged <30 days. Objectives were (1) to determine proportion and predictive factors for successful CCU collections using a stimulation maneuver technique among infants <6 months and (2) to determine the proportion of bacterial contamination with this method.

METHODS

A prospective cohort study was conducted in a tertiary pediatric emergency department among infants <6 months needing a urine sample. CCU samples were collected using a standardized stimulation technique. Invasive technique was performed after CCU for three specific conditions. Primary outcomes were proportions of successful CCU specimens and bacterial contamination. We determined associations between successful urine samples and 4 predictive factors (age, sex, low oral intake, and recent voiding).

RESULTS

A total of 126 infants were included (64 boys, median age: 55 days). The CCU procedure was effective in 62 infants (49%; median time: 45 seconds). Infants 0 to 29 days; 30 to 59 days, and 60 to 89 days had more successful procedures, compared with infants >89 days (odds ratios [95% confidence interval (CI)]: 4.3 [1.4 to 13.4]; 3.2 [1.2 to 8.4]; and 4.44 [1.5 to 13.3], respectively). The contamination proportion was 16% (95% CI: 8% to 27%) in the CCU group. This proportion was not statistically different compared with the invasive method group (6%, 95% CI: 3% to 15%).

CONCLUSIONS

The CCU procedure is a quick and effective noninvasive method in children aged <90 days. Contamination proportions were similar to those reported in the literature for urethral catheterization. Circumstances for which the CCU procedure could be performed are proposed.

The combination of urinary IL - 6 and renal biometry as useful diagnostic tools to differentiate acute pyelonephritis from lower urinary tract infection

OBJECTIVE

To evaluate the role of renal ultrasound (RUS) and urinary IL-6 in the differentiation between acute pyelonephritis (APN) and lower urinary tract infection (LUTI).

PATIENTS AND METHODS

This prospective study was carried out at the Pediatric and urology outpatient and inpatient departments of Cairo University Children's Hospital as well as October 6 University Hospital and it included 155 children between one month and fourteen years old with positive culture UTI. Patients were categorized into APN and LUTI based on their clinical features and laboratory parameters. Thirty healthy children, age and sex matched constituted the control group. Children with positive urine cultures were treated with appropriate antibiotics. Before treatment, urinary IL-6 was measured by enzyme immunoassay technique (ELISA), and renal ultrasound (RUS) was done. CRP (C-reactive protein), IL-6 and RUS were repeated on the 14th day of antibiotic treatment to evaluate the changes in their levels in response to treatment.

RESULTS

UIL-6 levels were more significantly higher in patients with APN than in patients with LUTI (24.3±19.3pg/mL for APN vs. 7.3±2.7pg/mL in LUTI (95% CI: 2.6-27.4; p< 0.01). Similarly, serum CRP was more significantly higher in patients with APN than in children with LUTI (19.7±9.1μg/mL vs. 5.5±2.3μg/mL (p< 0.01). IL-6 levels >20pg/mL and serum CRP >20μg/mL were highly reliable markers of APN. Mean renal volume and mean volume difference between the two kidneys in the APN group were more than that of the LUTI and control groups (P< 0.001). Renal volume between 120-130% of normal was the best for differentiating APN from LUTI.

CONCLUSIONS

RUS and urinary IL-6 levels have a highly dependable role in the differentiation between APN and LUTI especially in places where other investigations are not available and/ or affordable.

Increasing the Reliability of the Grading System for Voiding Cystourethrograms Using Ultrasonography: An Inter-Rater Comparison

BACKGROUND

To assess the effectiveness of the current vesicoureteral reflux (VUR) grading system according to the international classification of VUR (ICVUR) and to evaluate whether VUR grading accuracy could be improved by renal ultrasonography (RU) according to the Society for Fetal Urology (SFU) grading system.

OBJECTIVES

Therefore, this study assessed the accuracy of the current VCUG staging system by assessing inter-rater reliability among pediatric radiologists and urologists; it also evaluated whether accuracy is increased by RU without consensus (with respect to VCUG grading).

METHODS

Four pediatric urologists and four pediatric radiologists independently graded 120 voiding cystourethrograms (VCUGs). Middle VUR grades were divided into the following three groups: VUR consensus grade III (group 1), VUR consensus grade IV (group 3), and VUR non-consensus grades III and IV (group 2). All groups were compared with respect to hydronephrosis grade using RU.

RESULTS

The intraclass correlation coefficient (ICC) values ranging from 0.86 to 0.89 reflected good reliability. The lowest agreement was associated with middle grades (III and IV). A marked difference in sensitivity was observed between groups 1 and 3 (35% and 95%, respectively, P < 0.05), indexed by SFU hydronephrosis grade, suggesting that VCUG cases in group 2 (n = 16 at SFU 0 or 1) could be accepted as grade III, and SFU scores of 2, 3, or 4 could be considered grade IV.

CONCLUSIONS

Inter-rater accuracy could be improved at middle grades using renal ultrasonography (USG), which could promote communication between different specialists.

Dimercaptosuccinic acid scan or ultrasound in screening for vesicoureteral reflux among children with urinary tract infections

BACKGROUND

There is considerable interest in detecting vesicoureteral reflux (VUR) because its presence, especially when severe, has been linked to an increased risk of urinary tract infections and renal scarring. Voiding cystourethrography (VCUG), also known as micturating cystourethrography, is the gold standard for the diagnosis of VUR, and the grading of its severity. Because VCUG requires bladder catheterisation and exposes children to radiation, there has been a growing interest in other screening strategies that could identify at-risk children without the risks and discomfort associated with VCUG.

OBJECTIVES

The objective of this review is to evaluate the accuracy of two alternative imaging tests - the dimercaptosuccinic acid renal scan (DMSA) and renal-bladder ultrasound (RBUS) - in diagnosing VUR and high-grade VUR (Grade III-V VUR).

SEARCH METHODS

We searched MEDLINE, EMBASE, BIOSIS, and the Cochrane Register of Diagnostic Test Accuracy Studies from 1985 to 31 March 2016. The reference lists of relevant review articles were searched to identify additional studies not found through the electronic search.

SELECTION CRITERIA

We considered published cross-sectional or cohort studies that compared the results of the index tests (DMSA scan or RBUS) with the results of radiographic VCUG in children less than 19 years of age with a culture-confirmed urinary tract infection.

DATA COLLECTION AND ANALYSIS

Two authors independently applied the selection criteria to all citations and independently abstracted data. We used the bivariate model to calculate summary sensitivity and specificity values.

MAIN RESULTS

A total of 42 studies met our inclusion criteria. Twenty studies reported data on the test performance of RBUS in detecting VUR; the summary sensitivity and specificity estimates were 0.44 (95% CI 0.34 to 0.54) and 0.78 (95% CI 0.68 to 0.86), respectively. A total of 11 studies reported data on the test performance of RBUS in detecting high-grade VUR; the summary sensitivity and specificity estimates were 0.59 (95% CI 0.45 to 0.72) and 0.79 (95% CI 0.65 to 0.87), respectively. A total of 19 studies reported data on the test performance of DMSA in detecting VUR; the summary sensitivity and specificity estimates were 0.75 (95% CI 0.67 to 0.81) and 0.48 (95% CI 0.38 to 0.57), respectively. A total of 10 studies reported data on the accuracy of DMSA in detecting high-grade VUR. The summary sensitivity and specificity estimates were 0.93 (95% CI 0.77 to 0.98) and 0.44 (95% CI 0.33 to 0.56), respectively.

AUTHORS' CONCLUSIONS

Neither the renal ultrasound nor the DMSA scan is accurate enough to detect VUR (of all grades). Although a child with a negative DMSA test has an < 1% probability of having high-grade VUR, performing a screening DMSA will result in a large number of children falsely labelled as being at risk for high-grade VUR. Accordingly, the usefulness of the DMSA as a screening test for high-grade VUR should be questioned.

ROBO2 gene variants in children with primary nonsyndromic vesicoureteral reflux with or without renal hypoplasia/dysplasia

BACKGROUND

Primary nonsyndromic vesicoureteral reflux (VUR) and VUR with renal hypoplasia/dysplasia (VUR-RHD) are common congenital anomalies of the kidney and urinary tract (CAKUT). Sequence variations of the ROBO2 gene were investigated in children with nonsyndromic VUR or VUR-RHD.

METHODS

Single-strand conformation polymorphism (SSCP) electrophoresis or multiple restriction fragment SSCP (MRF-SSCP), followed occasionally by direct sequencing, was used to screen 103 patients and 200 controls for nucleotide changes. Gene polymorphisms and transposable elements were investigated using bioinformatics.

RESULTS

Two single-nucleotide polymorphisms were detected: IVS1-53 and IVS5-31. The frequency of A allele of IVS1-53G>A did not differ significantly between patients and controls. IVS1-53 does not affect mRNA splicing according to in silico analysis. IVS5-31A>G substitution was found in one patient, reported here for the first time in VUR. In silico results demonstrated alteration in two serine/arginine-rich (SR) protein-binding sites and two additional acceptor sites. The ROBO2 gene sequence was found to contain 25.9% transposable elements.

CONCLUSION

ROBO2 variants were not found to be associated with nonsyndromic VUR or VUR-RHD, providing further evidence for genetic heterogeneity. The role of transposable elements in ROBO2 gene expression in CAKUT needs further investigation since they are generally considered to be mutagens.

Urinary tract infection in the setting of vesicoureteral reflux

Vesicoureteral reflux (VUR) is the most common underlying etiology responsible for febrile urinary tract infections (UTIs) or pyelonephritis in children. Along with the morbidity of pyelonephritis, long-term sequelae of recurrent renal infections include renal scarring, proteinuria, and hypertension. Treatment is directed toward the prevention of recurrent infection through use of continuous antibiotic prophylaxis during a period of observation for spontaneous resolution or by surgical correction. In children, bowel and bladder dysfunction (BBD) plays a significant role in the occurrence of UTI and the rate of VUR resolution. Effective treatment of BBD leads to higher rates of spontaneous resolution and decreased risk of UTI.

Accuracy of ultrasonography in predicting vesicoureteral reflux in children: A meta-analysis

OBJECTIVE

The aim of this study was to assess the existing evidence on the accuracy of renal and bladder ultrasonography in predicting vesicoureteral reflux in children with first urinary tract infection.

MATERIALS AND METHODS

The CENTRAL, MEDLINE, Embase and Web of Science data sources were searched. A random effects meta-analysis was conducted.

RESULTS

Fourteen studies, involving 3544 participants, fulfilled the inclusion criteria. The risk of bias and concern regarding applicability were considered high in four studies. The pooled sensitivity was 0.37 [95% confidence interval (CI) 0.34 to 0.40], specificity 0.81 (95% CI 0.80 to 0.83), positive likelihood ratio 2.0 (95% CI 1.61 to 2.50), negative likelihood ratio 0.75 (95% CI 0.65 to 0.86), diagnostic odds ratio 3.03 (95% CI 2.10 to 4.37) and area under the curve 0.72.

CONCLUSION

There is no evidence that renal and bladder ultrasonography should be recommended as a test to predict a vesicoureteral reflux in children with their first urinary tract infection.

Value of Ultrasound in Detecting Urinary Tract Anomalies After First Febrile Urinary Tract Infection in Children

Background Urinary tract infection (UTI) is an infection that affects part of the urinary tract. Ultrasound is a noninvasive test that can demonstrate the size and shape of kidneys, presence of dilatation of the ureters, and the existence of anatomic abnormalities. The aim of the study is to estimate the value of ultrasound in detecting urinary tract anomalies after first attack of UTI. Methods This study was conducted at the Nephrology Clinic, New Children's Hospital, Faculty of Medicine, Cairo University, from August 2012 to March 2013, and included 30 children who presented with first attack of acute febrile UTI. All patients were subjected to urine analysis, urine culture and sensitivity, serum creatinine, complete blood count, and imaging in the form of renal ultrasound, voiding cysto-urethrography, and renal scan. Results All the patients had fever with a mean of 38.96°C ± 0.44°C and the mean duration of illness was 6.23 ± 5.64 days. Nineteen patients (63.3%) had an ultrasound abnormality. The commonest abnormalities were kidney stones (15.8%). Only 2 patients who had abnormal ultrasound had also vesicoureteric reflux on cystourethrography. Sensitivity of ultrasound was 66.7%, specificity was 37.5%, positive predictive value was 21.1%, negative predictive value was 81.8%, and total accuracy was 43.33%. Conclusion We concluded that ultrasound alone was not of much value in diagnosing and putting a plan of first attack of febrile UTI. It is recommended that combined investigations are the best way to confirm diagnosis of urinary tract anomalies.

Role of Renal Ultrasonography in Predicting Vesicoureteral Reflux and Renal Scarring in Children Hospitalized with a First Febrile Urinary Tract Infection

BACKGROUND

This study was designed to examine the capability of renal ultrasonography (US) for predicting vesicoureteral reflux (VUR) and renal scarring (RS), and to assess, using initial US, the significant urologic abnormalities that impact on management of children hospitalized with a first febrile urinary tract infection (UTI).

METHODS

Hospitalized children aged ≤ 2 years with a first febrile UTI were prospectively evaluated using imaging studies, including (99m)Tc dimercaptosuccinic acid (DMSA) scan, US, and voiding cystourethrography.

RESULTS

Of the 310 children analyzed (195 boys and 115 girls), 105 (33.9%) had abnormal US. Acute DMSA scans were abnormal in 194 children (62.6%), including 89 (45.9%) with concomitant abnormal US. There was VUR in 107 children (34.5%), including 79 (25.5%) with Grades III-V VUR. The sensitivity and negative predictive values of US were 52.3% and 75.1%, respectively, for Grades I-V VUR and 68.4% and 87.8%, respectively, for Grades III-V VUR. Eighty-five children (27.4%) had RS, including 55 (64.7%) with abnormal US. Of the 105 children with abnormal US, 33 (31.4%) needed subsequent management (surgical intervention, parental counseling, or follow up of renal function). Nephromegaly on initial US and Grades III-V VUR were risk factors of RS.

CONCLUSION

Abnormal US may carry a higher probability of Grades III-V VUR and RS, and can affect subsequent management in a significant number of children. Nephromegaly on initial US and Grades III-V VUR are strongly associated with an increased risk for RS. Thus, US should be performed on children after a first febrile UTI and children with normal US may not require voiding cystourethrography.

Contemporary Management of Vesicoureteral Reflux

The past 30 years have seen broad changes in the diagnosis and management of vesicoureteral reflux (VUR). Recently, a clinical debate has generated an open discussion in academic circles. New evidence has shifted treatment patterns away from widespread surgical management and recently brought into question some pharmacologic treatments. VUR is usually not hazardous by itself but is a significant risk factor for urinary tract infection (UTI) and less commonly, renal scarring and insufficiency. Given the costs and morbidity of UTI as well as the potential for significant renal injury, our approach remains conservative. Careful follow-up, parental education about pathophysiology and management of VUR and UTI, and management of bowel and bladder dysfunction (BBD) when present, are the foundation of treatment. Additionally, though we recognize the limitation of continuous antibiotic prophylaxis (CAP), we believe the benefits outweigh the risks and costs for many patients. Careful observation can be considered in patients with a single medical home, parental understanding of what UTI signs and symptoms are, low grade VUR, no history of complicated UTIs and close follow-up. Surgical management remains a relevant option for select patients who fail conservative measures with breakthrough UTIs or failure to resolve. Minimally invasive surgical options are available with acceptable outcomes though open ureteroneocystostomy still carries the highest success rate.

Reliability of the Grading System for Voiding Cystourethrograms in the Management of Vesicoureteral Reflux: An Interrater Comparison

Aim. Vesicoureteral reflux (VUR) is one of the most common conditions seen in pediatric urology. Fortunately, there are many treatment options for this disorder. The grading system for VUR varies among doctors, and the literature on its reliability is sparse. Here, we assessed the effectiveness of the current VUR grading system. Methods. A series of 40 voiding cystourethrogram (VCUG) studies were selected. Four pediatric urologists (PU) and four pediatric radiologists (PR) independently graded each VCUG and then agreed on a uniform interpretation. For statistical analysis the intraclass correlation coefficient (ICC) was applied to assess interrater agreement. Results. ICC values ranging from 0.82 to 0.88 reflected the strong reliability of VCUG for grading cases of VUR among pediatric urologists and radiologists as separate groups, and the reliability between the two groups was also good, as indicated by an ICC of 0.89. Despite the high ICC, disagreement existed between raters; the lowest agreement was associated with middle grades (III and IV). Conclusions. The interrater reliability of the international grading system for VUR was high but imperfect. Thus, grading differences at middle grades can profoundly influence the type of treatment pursued.

Renal ultrasound and DMSA screening for high-grade vesicoureteral reflux

BACKGROUND

Selection of the appropriate radiologic investigation in a child after first febrile urinary tract infection (UTI) remains a contentious issue. This report investigated the effectiveness of renal bladder ultrasound (RBUS) and late 6 month dimercaptosuccinic acid (DMSA) renal scan in the detection of high-grade vesicoureteral reflux (VUR) after first febrile UTI in infants aged <1 year.

METHODS

A total of 387 infants aged <1 year with first febrile UTI who completed diagnostic follow up consisting of RBUS, voiding cystourethrogram (VCUG) and late 6 month DMSA scan were enrolled in the study. The effectiveness of RBUS and DMSA scan in the detection of high-grade VUR, including cost and benefit were assessed.

RESULTS

Abnormal RBUS was identified in 95 infants (24.5%). VUR was identified on VCUG in 79 (20.4%), of whom eight (2.1%) had high-grade VUR (grade IV-V). Abnormal renal parenchyma was identified on late 6 month DMSA scan in 22 infants (5.7%). The sensitivity of abnormal RBUS and of late 6 month DMSA scan in the prediction of high-grade VUR was 50% and 87.5%, and the proportion of infants who avoided unnecessary VCUG was 75.5% and 94.3%, respectively.

CONCLUSIONS

Fifty percent of high-grade VUR was not identified on RBUS screening after first febrile UTI. Although late 6 month DMSA scan had higher sensitivity in the detection of high-grade VUR, with the added benefit of detection of renal scars, the practical application of this method was limited due to its high cost, radiation exposure and the associated delay in decision making.

'Targeted top down' approach for the investigation of UTI: A 10-year follow-up study in a cohort of 1000 children

INTRODUCTION

Investigations following urinary tract infection (UTI) aim to identify children who are prone to renal scarring, which may be preventable. In 2002, in an attempt to reduce unnecessary intervention, the present institution standardised the investigation of children with a confirmed UTI.

OBJECTIVE

This study aimed to identify the significance of urological abnormalities on investigations following a UTI in children, prior to the introduction of the National Institute for Health and Care Excellence (NICE) guidelines.

METHODS

Clinical information on the first 1000 patients was retrieved from a prospective UTI hospital database. The follow-up period was 10 years.

RESULTS

There were 180 males and 820 females (M:F = 1:4.5). The median age of presentation was 5 years (range 11 days-16 years). A renal ultrasound (US) was performed on all patients, and was normal in 93% of cases (n = 889) (see Figure). Of the 7% who had an abnormal US (n = 71), 54 were female and 17 male (M:F = 1:3). A total of 372 DMSA scans were requested and 350 attended their appointment. Of these, 278 cases (79%) were reported as normal, while 72 had an abnormality documented. Of these 72 patients with abnormalities on DMSA scan, 49 had a repeat DMSA scan: 30 demonstrated permanent scarring, while the DMSA scan became normal in 19. Sixteen of the 278 patients whose DMSA scan was initially normal had a repeat DMSA scan due to symptoms, and all scans were normal. Twelve (1.2%) patients required surgical intervention: three underwent circumcision for recurrent UTIs; three underwent endoscopic treatment of VUR; one had a PUV resection; one underwent a cystoscopy; three had a pyeloplasty for pelvi-ureteric junction obstruction; and one had a ureteric reimplantation for vesico-ureteric junction obstruction. After initial investigations and management, 936 patients were discharged from the UTI clinic: 47 of them re-presented - 40 with recurrent UTIs and seven with dysuria. Thirty-five of the 47 children who re-presented with urological symptoms underwent a DMSA scan, which showed scarring in three (6%).

DISCUSSION

Only 12% of children have a significant radiological abnormality picked up on investigation following a UTI. The present investigation approach differed from the NICE guidelines, where imaging is based on patient age and characteristics of the UTI. All children had a renal US, while DMSA scans were reserved for those children <1 year of age or those with upper tract symptoms. The present protocol recommended a renal US in all children presenting with a UTI. This promptly identified those with pelvi-ureteric junction obstruction and those with PUV, who all presented >6 months of age with a single UTI and, therefore, based on the NICE guidelines would not have undergone a renal US. Of the children who re-presented with further UTIs, a significant number were found to have dysfunctional voiding. As this link is well reported, it may be appropriate to screen for this in older children at initial presentation. Only three patients, who had a US at presentation, were subsequently found to have scarring on DMSA. After 10 years of follow-up, this could represent a false negative rate of 0.3% for the screening programme. None of the girls were found to have VUR or needed any surgical intervention, which suggested that early identification of the scarring might not have altered management. Few patients required surgical intervention, all of whom were identified early. No patient who re-presented required intervention. This would suggest that the present protocol is effective at picking up abnormalities that require surgical management.

CONCLUSION

This study suggested that after a childhood UTI, the liberal use of renal ultrasound and a focused 'top down' approach to investigation is likely to identify the vast majority of children who require intervention.

Urinary tract infection in infants: the significance of low bacterial count

BACKGROUND

In national guidelines for urinary tract infection (UTI) in children, different cut-off levels for defining bacteriuria are used. In this study, the relationship between bacterial count in infant UTI and inflammatory parameters, frequency of vesicoureteral reflux (VUR), kidney damage, and recurrent UTI was analyzed.

METHODS

We conducted a population-based retrospective study of 430 infants age <1 year with symptomatic UTI diagnosed by suprapubic aspiration. Clinical and laboratory parameters, findings on voiding cystourethrography and (99m)technetium dimercapto-succinic acid scintigraphy, and frequency of recurrence were related to bacterial count at the index UTI.

RESULTS

Eighty-three (19%) infants had bacterial counts <100,000 colony-forming units (CFU)/ml and 347 (81%) had ≥100,000 CFU/ml. There was similar frequency of VUR (19% in both groups), kidney damage (17 and 23%, p = 0.33) and recurrent UTI (6 and 12%, p = 0.17) in the low and high bacterial group. Non-E. coli species were more prevalent (19 versus 6%, p = 0.0006) and mean C-reactive protein was lower (50 vs. 79 mg/l, p <0.0001) in the low bacteria group.

CONCLUSIONS

UTI with low bacterial count is common and of importance since it may be associated with VUR and renal damage. Non-E. coli species and low inflammatory response were more prevalent in UTI with low bacterial count.

Value of sonographic anterior-posterior renal pelvis measurements before and after voiding for predicting vesicoureteral reflux in children

PURPOSE

Voiding cystourethrography (VCUG) is the gold standard for diagnosing vesicoureteral reflux (VUR), but it is important to minimize the use of VCUG because of the urinary catheterization and radiation exposure required. Ultrasound (US) observations suggest that pelvicalyceal dilatation varies according to the degree of bladder fullness in children with urinary tract infection. The aim of this study was to assess whether anterior-posterior (AP) measurements of the renal pelvis on US before and after voiding can be used as a screening tool while predicting the presence of VUR in children.

METHODS

The subjects were toilet-trained children older than 4 years who required VCUG. Two groups were established based on the VCUG results: a VUR group of 40 kidney units (each unit defined as calyces and ureter) that exhibited different severities of reflux, and a control group of 68 kidney units unaffected by VUR. Prior to VCUG, US AP measurements of the renal pelvis of each kidney unit were recorded when the urinary bladder was full and again after bladder emptying. The change in AP measurement from before to after voiding was compared between the two groups.

RESULTS

The mean change in AP measurements from before to after voiding in the VUR group was significantly greater than that in the control group (p = 0.003).

CONCLUSIONS

Comparing US AP measurements of the renal pelvis before and after voiding is useful for identifying children who are suspected to have VUR and thus require immediate VCUG.

The role of tissue harmonic imaging ultrasound combined with power Doppler ultrasound in the diagnosis of childhood febrile urinary tract infections

AIM

This study assessed the ability of tissue harmonic imaging ultrasound combined with power Doppler ultrasound in the detection of childhood febrile urinary tract infections in comparison with the gold standard reference method: Tc-99m dimercaptosuccinicacid renal cortical scintigraphy.

MATERIAL AND METHODS

This prospective study included 60 patients who were hospitalized with a first episode of febrile urinary tract infections. All children were examined with dimercaptosuccinicacid scan and tissue harmonic imaging ultrasound combined with power Doppler ultrasound within the first 3 days of admission.

RESULTS

Signs indicative of acute infection were observed in 29 patients according to the results of tissue harmonic imaging ultrasound combined with power Doppler ultrasound while dimercaptosuccinicacid scan revealed abnormal findings in 33 patients. The sensitivity, specificity, positive predictive value and negative predictive value of tissue harmonic imaging combined with power Doppler ultrasound using dimercaptosuccinicacid scintigraphy as the reference method in patients diagnosed with first episode febrile urinary tract infections were calculated as 57.58% (95% confidence interval: 40.81%-72.76%); 62.96% (95% confidence interval: 44.23%-78.47%); 65.52% (95% confidence interval: 52.04%-77%); 54.84% (95% confidence interval: 41.54%-67.52%); respectively.

CONCLUSIONS

Although current results exhibit inadequate success of power Doppler ultrasound, this practical and radiation-free method may soon be comprise a part of the routine ultrasonographic evaluation of febrile urinary tract infections of childhood if patients are evaluated early and under appropriate sedation.

Work-up of Pediatric Urinary Tract Infection

Pediatric urinary tract infection (UTI) costs the health care system more than $180 million annually, and accounts for more than 1.5 million clinician visits per year. Accurate and timely diagnosis of these infections is important for determining appropriate treatment and preventing long-term complications such as renal scarring, hypertension, and end-stage renal disease. After the first 12 months, girls are more likely to be diagnosed with a UTI. About half of boys with UTI are diagnosed within the first 12 months of life. Diagnosis of UTI is made based on history and examination findings and confirmed by urine testing.

Predictive value of specific ultrasound findings when used as a screening test for abnormalities on VCUG

BACKGROUND

Renal and bladder ultrasound (RBUS) is often used as an initial screening test for children after urinary tract infection (UTI), and the 2011 AAP guidelines specifically recommend RBUS be performed first, with voiding cystourethrogram (VCUG) to be performed only if the ultrasound is abnormal. It is uncertain whether specific RBUS findings, alone or in combination, might make RBUS more useful as a predictor of VCUG abnormalities.

AIMS

To evaluate the association of specific RBUS with VCUG findings, and determine whether predictive models that accurately predict patients at high risk of VCUG abnormalities, based on RBUS findings, can be constructed.

METHODS

and study sample: A total of 3995 patients were identified with VCUG and RBUS performed on the same day. The RBUS and VCUG reports were reviewed and the findings were classified. Analysis was limited to patients aged 0-60 months with no prior postnatal genitourinary imaging and no history of prenatal hydronephrosis.

ANALYSIS

The associations between large numbers of specific RBUS findings with abnormalities seen on VCUG were investigated. Both multivariate logistic models and a neural network machine learning algorithms were constructed to evaluate the predictive power of RBUS for VCUG abnormalities (including VUR or bladder/urethral findings). Sensitivity, specificity, predictive values and area under receiving operating curves (AUROC) of RBUS for VCUG abnormalities were determined.

RESULTS

A total of 2259 patients with UTI as the indication for imaging were identified. The RBUS was reported as "normal" in 75.0%. On VCUG, any VUR was identified in 41.7%, VUR grade > II in 20.9%, and VUR grade > III in 2.8%. Many individual RBUS findings were significantly associated with VUR on VCUG. Despite these strong univariate associations, multivariate modeling didn't result in a predictive model that was highly accurate. Multivariate logistic regression built via stepwise selection had: AUROC = 0.57, sensitivity = 86% and specificity = 25% for any VUR; AUROC = 0.60, sensitivity = 5% and specificity = 99% for VUR grade > II; and AUROC = 0.67, sensitivity = 6% and specificity = 99% for VUR grade > III. The best predictive model constructed via neural networks had: AUROC = 0.69, sensitivity = 64% and specificity = 60% for any VUR; AUROC = 0.67, sensitivity = 18% and specificity = 98% for VUR grade > II; and AUROC = 0.79, sensitivity = 32% and specificity = 100% for VUR grade > III.

CONCLUSIONS

Even with the state-of-the-art predictive models, abnormal findings on RBUS provide a poor screening test for genitourinary abnormalities. Renal bladder ultrasound and VCUG should be considered complementary, as they provide important, but different, information.

Bacteremia in children: epidemiology, clinical diagnosis and antibiotic treatment

The diagnosis of bacteremia in children is important and it can be clinically challenging to recognize the signs and symptoms. The reported rates of bacteremia are higher in young children but with the increasing vaccine coverage, there has been a decrease in bacteremia due to the three vaccine preventable bacteria (Streptococcus pneumoniae, Haemophilus influenzae group b and Neisseria meningitidis). Notably, there have been increases in healthcare-associated bacteremias with a rise in Staphylococcus aureus and Gram negative bacteremias. This review provides a brief overview of the clinical diagnosis of bacteremia in children, focusing on the epidemiology, clinical characteristics, risk factors, antibiotic treatment, outcomes and preventative measures to reduce the incidence of bacteremia and improve morbidity and mortality.

Risk Factors for Recurrent Urinary Tract Infection and Renal Scarring

OBJECTIVES

To identify risk factors for recurrent urinary tract infection (UTI) and renal scarring in children who have had 1 or 2 febrile or symptomatic UTIs and received no antimicrobial prophylaxis.

METHODS

This 2-year, multisite prospective cohort study included 305 children aged 2 to 71 months with vesicoureteral reflux (VUR) receiving placebo in the RIVUR (Randomized Intervention for Vesicoureteral Reflux) study and 195 children with no VUR observed in the CUTIE (Careful Urinary Tract Infection Evaluation) study. Primary exposure was presence of VUR; secondary exposures included bladder and bowel dysfunction (BBD), age, and race. Outcomes were recurrent febrile or symptomatic urinary tract infection (F/SUTI) and renal scarring.

RESULTS

Children with VUR had higher 2-year rates of recurrent F/SUTI (Kaplan-Meier estimate 25.4% compared with 17.3% for VUR and no VUR, respectively). Other factors associated with recurrent F/SUTI included presence of BBD at baseline (adjusted hazard ratio: 2.07 [95% confidence interval (CI): 1.09-3.93]) and presence of renal scarring on the baseline (99m)Tc-labeled dimercaptosuccinic acid scan (adjusted hazard ratio: 2.88 [95% CI: 1.22-6.80]). Children with BBD and any degree of VUR had the highest risk of recurrent F/SUTI (56%). At the end of the 2-year follow-up period, 8 (5.6%) children in the no VUR group and 24 (10.2%) in the VUR group had renal scars, but the difference was not statistically significant (adjusted odds ratio: 2.05 [95% CI: 0.86-4.87]).

CONCLUSIONS

VUR and BBD are risk factors for recurrent UTI, especially when they appear in combination. Strategies for preventing recurrent UTI include antimicrobial prophylaxis and treatment of BBD.

Urinary neutrophil gelatinase-associated lipocalin (NGAL) might be an independent marker for anticipating scar formation in children with acute pyelonephritis

INTRODUCTION

Urinary tract infections (UTIs) are the most serious common bacterial infections among young children. It may affect kidneys that classified as acute pyelonephritis (APN) and may lead to renal parenchymal involvement and scarring with high prevalence rate (15%-60%) among children. This study aimed to assess the urinary concentration of neutrophil gelatinase-associated lipocalin (NGAL) in patients with APN to diagnose those with potency to scar formation.

PATIENTS AND METHODS

Children who were admitted with a diagnosis of APN were enrolled and divided into two groups; APN with scar and APN without scar. Urinary levels of NGAL and its ratio to creatinine (Cr) levels were measured in the acute phase of infection. A receiver operating characteristic (ROC) curve was generated to allow calculation of cut-off values.

RESULTS

Fifty-four children were enrolled across the 2 groups: group 1 consisted of 16 patients (all female); group 2 consisted of 38 children (36 female and 2 male). Urinary levels of NGAL were significantly higher in APN with scar than in APN without scar (P = 0.037). For comparison of groups 1 and 2, the cut-off values were measured as 7.32 ng/ml, sensitivity; 81.3% and specificity; 66%.

CONCLUSION

Evaluation of urinary NGAL levels may help us to identify children with APN who are at risk of developing renal scarring.

Uroepithelial Thickening on Sonography Improves Detection of Vesicoureteral Reflux in Children with First Febrile Urinary Tract Infection

PURPOSE

The 2011 American Academy of Pediatrics clinical practice guideline for childhood febrile urinary tract infection recommends voiding cystourethrography if renal and bladder ultrasound reveals hydronephrosis, scarring or "other findings" that suggest high grade vesicoureteral reflux. We sought to determine if the finding of uroepithelial thickening indicates greater risk of high grade vesicoureteral reflux and whether uroepithelial thickening improves the screening value of renal and bladder ultrasound.

MATERIALS AND METHODS

We retrospectively analyzed renal and bladder ultrasound and voiding cystourethrogram findings in children 2 to 24 months old with first febrile urinary tract infection during an 11-year period. Patients with uroepithelial thickening were compared to an age and gender matched sample without uroepithelial thickening. Logistic regression was used to identify factors associated with high grade vesicoureteral reflux. Test characteristics of renal and bladder ultrasound for high grade reflux were compared based on different criteria to define an abnormal renal and bladder ultrasound.

RESULTS

Of 226 patients 143 (63%) had vesicoureteral reflux, of whom 37 (26%) had high grade reflux. On multivariable analysis uroepithelial thickening was a significant independent predictor of high grade vesicoureteral reflux (OR 5.41, 95% CI 1.74-16.79, p = 0.004). When hydronephrosis and hydroureter were considered the only abnormal renal and bladder ultrasound findings warranting voiding cystourethrography, sensitivity of renal and bladder ultrasound for high grade reflux was 84%, and 6 children with high grade and 82 with low grade reflux would have been missed. When uroepithelial thickening was also considered an abnormal finding, the sensitivity increased to 97%, and only 1 child with high grade and 57 with low grade reflux would have been missed.

CONCLUSIONS

Uroepithelial thickening is associated with an increased risk of high grade vesicoureteral reflux and is an abnormal finding warranting voiding cystourethrography. Sensitivity of renal and bladder ultrasound as a screening test for high grade vesicoureteral reflux is markedly improved when uroepithelial thickening is considered.

Ultrasonography and C-reactive protein can predict the outcomes of voiding cystography after the first urinary tract infection

AIM

This study evaluated whether sex, clinical variables, laboratory variables or ultrasonography predicted the presence of vesicoureteric reflux during the first episode of urinary tract infection in paediatric patients. We also aimed to define the criteria that indicated the need for voiding cystography testing.

METHODS

We used voiding cystography to investigate 200 patients who experienced their first urinary tract infection at our institution between 2004 and 2013 and retrospectively analysed the data by reviewing their medical records.

RESULTS

Sex (p = 0.001), peak blood C-reactive protein levels (p < 0.001), the duration of fever after antibiotic administration (p = 0.007) and the ultrasonography findings grade (p < 0.001) were significantly different between patients with and without vesicoureteric reflux. Grade IV-V ultrasonography findings and C-reactive protein levels of ≥80 mg/L predicted vesicoureteric reflux with a sensitivity, specificity and odds ratio of 47.8%, 87.8% and 6.59 (95% confidence interval = 3.26-13.33), respectively (p < 0.001).

CONCLUSION

Voiding cystography should be performed for patients with C-reactive protein levels of ≥80 mg/L and grade IV-V ultrasonography findings, but is not necessary in patients with C-reactive protein levels of <80 mg/L and grade I-III ultrasonography findings.

Urinary tract infection in children younger than 5 years. Etiology and associated urological anomalies

OBJECTIVES

To investigate the most common underlying organisms, and associated urological anomalies in children presenting with urinary tract infection (UTI).

METHODS

Retrospectively, all children with confirmed UTI between October 2013 and February 2014 were evaluated at King Abdulaziz University Hospital, Riyadh, Kingdom of Saudi Arabia. The electronic files of 279 children presenting with UTI, aged less than 5 years were reviewed.

RESULTS

A total of 153 patients (85 males) with a mean (SD) age of 15 (19.86) months were included in the study. Recurrent UTI was present in 45.1%. Urine collection in children less than 2 years of age was through trans-urethral catheterization in 69.4%, while midstream urine was the main method in those above 2 years (78.6%). Escherichia coli (E. coli) was the causative organism in 41.2% of first UTI. The second most common organism was Klebsiella Pneumoniae, seen in 19.6%. Urological anomalies were found in 28.1% of the overall study population. Ninety percent of those with single UTI did not have anomalies. However, urological anomalies were reported in 50.7% of those with recurrent episodes of UTI (p less than 0.005). Non-E. coli cases were associated with a higher percentage of abnormal renal ultrasonography results (p=0.006).

CONCLUSION

Escherichia coli was the most common causative organism for UTI, and a single episode of UTI signified normal urological anatomy.

Incidence of antibiotics resistance among uropathogens in Omani children presenting with a single episode of urinary tract infection

Urinary tract infection (UTI) is one of the most common community-acquired infections. Different organisms can be the cause of UTI in children, with resistance to antibiotics becoming a significant problem in the choice of treatment. Worldwide studies have documented the prevalence of uropathogens in different countries. However, there is no previous study documenting the incidence of different uropathogens in Oman. We aim to report the most common uropathogens and their antibiotic sensitivity patterns in children presenting with documented, single episode UTI at a tertiary hospital in Oman. A retrospective analysis of all Omani children below 14 years who presented with a case of first documented UTI to SQUH between September 2008 and August 2012 was conducted. Data were obtained from the patients' electronic records in the hospital information system. Data were then analyzed using SSPS (Statistical Package for Social Sciences program, Version 20, IBM, Chicago, IL, USA). In the retrospective review of all urine cultures, 438 positive urine cultures were identified. Out of those, 208 (47.5%) belonged to children with their first episode of UTI. Thirty-three patients were excluded and 75 patients were included in the final analysis. Escherichia coli was the most frequently encountered uropathogen in our cohort (69%), followed by Klebsiella pneumoniae infection (17%). Nearly half (46.6%) of these two common organism were resistant to Cotrimoxazole, while 31% of them were resistant to Augmentin. Twenty-four percent of the E. coli and K. pneumoniae strains were resistant to Cefuroxime, and only 10% were resistant to nitrofurantoin. Both Augmentin and Cotrimoxazole should not be the first line antibiotics to treat UTI.

Consequences of following the new American Academy of Pediatrics guidelines for imaging children with urinary tract infection

OBJECTIVE

Urinary tract infections (UTIs) and vesicoureteral reflux (VUR) are assumed to predispose children to renal damage. Awareness of the significance of VUR and the possibility of reducing UTI recurrence and renal damage has warranted guidelines on which patients should undergo imaging after UTI. An authoritative guideline has been issued by the American Academy of Pediatrics (AAP). This study assessed the applicability of the AAP guidelines to a subpopulation of patients with UTI, 2-24-month-old children with febrile UTI.

MATERIALS AND METHODS

The records of 394 children aged 2-24 months with their first UTI were reviewed. Data were recorded on the indications for renal and bladder ultrasonography (RBUS) and voiding cystourethrography (VCUG) according to the AAP guidelines, RBUS results, VCUG results, use of antimicrobial prophylaxis, antireflux procedures and other urological treatment, and UTI recurrence.

RESULTS

An indication for RBUS was seen in 344 patients. RBUS results were abnormal in 87, including 53 with urinary tract dilatation. An unnecessary RBUS would have been avoided in 43 patients. Seven patients with an abnormal RBUS would not have undergone RBUS. An indication for VCUG was seen in 126 patients. VCUG was performed in 206 patients; VUR was found in 72 patients, including 36 with high-grade VUR. An unnecessary VCUG would have been avoided in 82 patients. High-grade VUR would have been missed in six patients. Five patients would not have undergone surgery.

CONCLUSION

The AAP guidelines for imaging studies in children aged 2-24 months with febrile UTI seem applicable to clinical practice.

Evaluation and management of recurrent urinary tract infections in children: state of the art

Urinary tract infections (UTIs) represent an important cause of febrile illness in young children and can lead to renal scarring and kidney failure. However, diagnosis and treatment of recurrent UTI in children is an area of some controversy. Guidelines from the American Academy of Pediatrics, National Institute for Health and Clinical Excellence and European Society of Paediatric Radiology differ from each other in terms of the diagnostic algorithm to be followed. Treatment of vesicoureteral reflux and antibiotic prophylaxis for prevention of recurrent UTI are also areas of considerable debate. In this review, we collate and appraise recently published literature in order to formulate evidence-based guidance for the diagnosis and treatment of recurrent UTI in children.